diff --git a/ggml-opencl.cpp b/ggml-opencl.cpp
index 40a13978d..e28566a7b 100644
--- a/ggml-opencl.cpp
+++ b/ggml-opencl.cpp
@@ -926,7 +926,7 @@ static cl_program build_program_from_source(cl_context ctx, cl_device_id dev, co
 
     std::string compile_opts = "-cl-mad-enable -cl-unsafe-math-optimizations -cl-finite-math-only -cl-fast-relaxed-math "
                                "-DQK4_0=32 -DQR4_0=2 -DQK4_1=32 -DQR4_1=2 -DQK5_0=32 -DQR5_0=2 -DQK5_1=32 -DQR5_1=2 -DQK8_0=32 -DQR8_0=1 "
-                               "-DK_QUANTS_PER_ITERATION=" + std::to_string(K_QUANTS_PER_ITERATION);
+                               "-DQK_K=256 -DK_QUANTS_PER_ITERATION=" + std::to_string(K_QUANTS_PER_ITERATION);
 
     err = clBuildProgram(p, 0, NULL, compile_opts.c_str(), NULL, NULL);
     if(err < 0) {